Systemic glutamate induces degeneration of a subpopulation of serotonin-immunoreactive neurons in the area postrema of rats.
Neuronal damage in the area postrema (AP) of adult Sprague-Dawley rats was induced by subcutaneous administration of monosodium glutamate (MSG; 9 mg/g b.wt.). Serotonin-immunoreactive (5-HT-IR) neurons were visualized in the AP 3 h or 7 days after control or MSG treatment. At 3 h post MSG, many 5-HT-IR neurons showed morphological signs of degeneration, such as, cytoplasmic vacuolization, chromatin clumping and dendritic hypertrophy. MSG treatment caused a 30% reduction of detectable AP 5-HT neurons after 7 days. We conclude that a subpopulation of serotonergic neurons in the AP is sensitive to the neuroexcitotoxic effect of systemic glutamate.
Phelix
C F
CF
Department of Pharmacology and Toxicology, College of Pharmacy, University of Georgia, Athens 30602.
Hartle
D K
DK
D000818:Animals; D002552:Cerebral Ventricles / Q000187:drug effects / Q000473:pathology*; D005998:Glycine / Q000494:pharmacology; D007124:Immunoenzyme Techniques; D008297:Male; D009410:Nerve Degeneration / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000473:pathology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000032:analysis*; D012970:Sodium Glutamate / Q000633:toxicity*; D014364:Tryptophan / Q000494:pharmacology
D012701:Serotonin; D014364:Tryptophan; D005998:Glycine; D012970:Sodium Glutamate